An image forming apparatus includes a patch image generation unit which generates a patch image for image density detection disposed between toner images, and a patch density sensor which detects a density of the patch image. In order to prevent the output quality of a printed image from varying with the type of paper use, a correction unit performs correction processing to match a detected density and a target density by comparing the detected density of the patch image detected by the patch density sensor and the target density of the patch image which is set in advance, a toner deposit control unit controls a toner deposit when the image forming unit forms an image based upon image data and when the patch image generation unit generates the patch image, and a paper interval control unit controls an interval between consecutive papers.
Legal claims defining the scope of protection, as filed with the USPTO.
1. An image forming apparatus, comprising: an image forming unit which forms an image on a paper based on image data; an image carrier on which a toner image is formed by the image forming unit; a patch image generation unit which generates a patch image for image density detection disposed between toner images of images formed consecutively on the image carrier; a patch density sensor which detects a density of the patch image generated by the patch image generation unit; a correction unit which performs correction processing to match a detected density and a target density by comparing the detected density of the patch image detected by the patch density sensor and the target density of the patch image which is set in advance; a toner deposit control unit which controls a toner deposit when the image forming unit forms the image based on the image data and when the patch image generation unit generates the patch image; and a paper interval control unit which controls an interval between consecutive papers, wherein in a case in which the toner deposit has been changed to be greater than a predetermined standard value and the patch image is to be generated by the patch image generation unit, the paper interval control unit executes a paper interval broadening processing to make the interval between consecutively conveyed papers be longer than a standard interval, and the toner deposit control unit executes a toner deposit changing processing to return the toner deposit to the predetermined standard value so that the patch image is formed with the predetermined standard value of the toner deposit.
2. The image forming apparatus of claim 1 , further comprising: a setting unit which sets the correction processing to be prohibited when the toner deposit is greater than the predetermined standard value; and an informing unit which informs that the patch image is not to be generated when the setting unit sets the correction processing be prohibited, wherein when the setting unit sets the correction processing be prohibited, the paper interval control unit does not execute the paper interval broadening processing and the toner deposit control unit does not execute the toner deposit changing processing.
3. The image forming apparatus of claim 2 , wherein the image forming unit periodically stops operation when the setting unit sets the correction processing to be prohibited, and the patch image generation unit generates the patch image during a periodic stop period of the image forming unit.
4. The image forming apparatus of claim 1 , wherein the toner deposit control unit changes the toner deposit for each color.
5. The image forming apparatus of claim 4 , wherein the paper interval control unit is controlled to execute the paper interval broadening processing and the toner deposit control unit is controlled to execute the toner deposit changing processing only when the patch image generation unit generates the patch image in a same color as a color in which the toner deposit is set to be greater than the predetermined standard value.
6. The image forming apparatus of claim 4 , wherein when the toner deposit is changed only with respect to a black toner by the toner deposit control unit, the patch image generation unit prohibits generation of a black patch image, and when the toner deposit is changed with respect to at least one color of toner other than black by the toner deposit control unit, the patch image generation unit prohibits generation of patch images of all colors.
7. The image forming apparatus of claim 6 , wherein when the patch image generation unit stops generation of the patch image of at least one of black or all colors other than black, the image forming unit periodically stops operation, and the patch image generation unit generates the black patch image or the patch images of all colors other than black during a periodic stop period of the image forming unit.
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March 9, 2012
September 23, 2014
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